This invention relates to metal pan steel and precast concrete stair construction; in particular to adjustable metal pan profiles for production of stairs which ideally suit the human step length on an incline and also comply with building code requirements. Instead of manufacturing custom dimensioned sheet metal pan forms for each specific riser and run condition, this invention makes it possible to cover all riser and run relations that occur in buildings. This is achieved by sliding individual pan profiles against each other as described in the summary of the invention and detailed description hereinafter.